The present invention relates in general to printed circuit board (PCB) in-circuit test (ICT) methods and structures. More specifically, the present invention relates to ICT probe structures having an improved probe-to-via contact and methods of using the same.
Circuit boards such as multilayer printed circuit boards (PCBs) are widely used in the electronics industry. PCBs typically include one or more layers having conductive traces etched onto them, the various layers separated by a dielectric material. Interconnections are possible between each layer, for example using through-holes or vias. PCB design and production is often subject to various, often conflicting, requirements, such as a demand for products which are compact, operate at high-speeds, have low costs, and have high reliability. Meeting these requirements presents an ongoing challenge for the industry.
In-circuit tests (ICTs) are widely used throughout the industry to improve PCB reliability and quality control. ICTs assess the electrical properties of electrical elements in PCBs and the quality of the electrical connections between the electrical elements. ICTs measure the resistances, capacities, and other characteristics of each electrical element to detect potential manufacturing defects and the reliability of each electrical element tested. For example, an ICT can identify open or short circuits. ICTs offer simple operation requirements and accurate defect positioning.